Slashdot videos: Now with more Slashdot!

View

Discuss

Share

We've improved Slashdot's video section; now you can view our video interviews, product close-ups and site visits with all the usual Slashdot options to comment, share, etc. No more walled garden! It's a work in progress -- we hope you'll check it out (Learn more about the recent updates).

Any astrophysicists (or at least postgrads) here to say how important or true this achievement really is?

The article (got to it prior Newton's First Law of./ effect) actually did quite a good job of addressing exactly that.

Takeaways were:-Missing mass (not dark matter, but matter which was seen to exist during creation of universe but is now someplace different) turns out to have migrated to filaments that span across the universe.-Claimed that astrophysicists have long postulated (~2 decades) that the mass had moved there, but that the imaging capabilities weren't able to resolve it.-Then in a fit of bipolar impetus, also went on to say how exciting a discovery this was for the community.-Finally acknowledged that most likely nothing useful (to mankind) will come of this discovery.

-Finally acknowledged that most likely nothing useful (to mankind) will come of this discovery.

Well... if it fulfills some predictions then it possibly validates some theories. If nothing else, maybe the scientists who were collectively looking for this missing mass can now go on to something useful:)

Any astrophysicists (or at least postgrads) here to say how important or true this achievement really is?

It's fairly significant. They have confirmed that some fraction of the missing baryonic matter (the ordinary stuff we are made of, like Galactic Dark Matter, not the exotic new-particle stuff) is in the filaments that exist on very large scales in the universe. If they had failed to find it the result would have been more interesting, but even so they've done a good bit of science by testing the idea that the missing baryonic matter is in these filaments by actually going and looking for it rather than taking it on faith that it must be there.

We know there is missing baryonic matter because we know what the baryonic density in the universe is from the primordial helium/hydrogen ratio. Free neutrons only live about fifteen minutes, so as the Big Bang cooled and neutrons and protons condensed out of the primordial quark-gluon plasma there was a relatively short interval in which helium could form. We know the size of the universe at that time from the temperature, and we know the density because the denser it was the more neutrons would have been captured onto protons to form heavier isotopes, so by figuring out the primordial density of deuterium, helium and lithium we can put pretty strong constraints on the total baryonic mass of the universe.

I find it unnerving that people/scientists claim to know things when they only think they know them

I find it amusing that on the one hand you claim not to to know anything about physics (and clearly you don't, nor science in general) and then try to bolster your skeptical position based on claims that come directly from modern physics.

Skepticism is not a self-consistent position: to motivate it skeptics have to claim that they know things, and that their knowledge of those things (from sensory illusions to radical meaning variance to the simple complexity of the universe) justifies their skepticism.

I find it amusing that on the one hand you claim not to to know anything about physics (and clearly you don't, nor science in general) and then try to bolster your skeptical position based on claims that come directly from modern physics.

A) I said I claimed not have read/understood any of the physics that was used to make your claims - not that I haven't read or grasped any physics. B) The modern-physics I did reference, I used uncertain terms when referencing it - "It appears that..." - not - "It is a fact that...." - a distinction that is what my whole post was about. Stating things in certain terms when they are only known in uncertain terms - the best evidence we have, the best theory we have - are not definitively true and it bothers

I just wish some astrophysicists (or the people who quote/repeat them, not sure who's at fault) would bring humility to their ideas and realize that even after a life-time of thinking and studying they are still no different than an 18 year old just getting out of high school that doesn't know shit about shit.

I think it's more likely you don't know shit about shit. Yes, the word "know" is used loosely, but in general means "all the experimental evidence obtained so far points to this being true within some specified reasonable error margins". Whereas you don't appear even have a basic understanding of the theory being applied (by your own admission) or the experimental evidence available, and yet you feel qualified to comment on whether people "know" things or not.

And you know the temperature of the Universe at the moment of the big bang, how? You're not extrapolating anything or making assumptions about the nature of things before the things ever existed and that similar rules apply? I think you are. I think you'd be arrogant to assume you know anything about the nature of things when the Universe as we know it didn't yet exist.

A minute is 60 seconds where a second is defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom. Which is the same throughout the entire the universe and to the best of our knowledge the same for all time.

I love quotes like these, as they prove the religious nature of modern science. Hidden for the most part, but still dependent upon "faith". A belief in things unseen.

You don't know that the period of the transition is the same throughout the entire universe, or the same for all time. You assume it because you don't have any reason to think it will be different. That's still an assumption.

Of course, you could be saying that the number 9+ billion is the same throughout the universe and not that the actual

and yet you feel qualified to comment on whether people "know" things or not.

Yes, I do. If it is called a theory, then no one knows it is true, they may think it is true, they may believe it is true - but they do not know it to be true. My entire post was about how people sound and choose their words to make their statements appear more authoritative than they really are. I'm am not saying the parent's claims are wrong or are incorrect - I was only pointing out that they are not absolutely 100% correct which is how he chose to state it. I am aware of what scientists mean when they s

The SI units have been defined in non-Earth centric ways for many many years now. A minute is 60 seconds where a second is defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom. Which is the same throughout the entire the universe and to the best of our knowledge the same for all time.

This measurement suffers from the same problem. Define a second at a point in time when a caesium-133 atom had never existed. We base our units of time on things that exist today and still don't even really have a solid grasp of what we are even measuring. At least, I have never heard of anyone claim to have a complete understanding of time, what it is, whether it exists naturally or is purely a construct of (human) consciousness and exactly how we all travel through it. Personall

The SI units have been defined in non-Earth centric ways for many many years now. A minute is 60 seconds where a second is defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom. Which is the same throughout the entire the universe and to the best of our knowledge the same for all time.

This measurement suffers from the same problem. Define a second at a point in time when a caesium-133 atom had never existed. We base our units of time on things that exist today and still don't even really have a solid grasp of what we are even measuring. At least, I have never heard of anyone claim to have a complete understanding of time, what it is, whether it exists naturally or is purely a construct of (human) consciousness and exactly how we all travel through it..

I don't know about complete, but Stephen Hawkings "A Brief History of Time" (and the real physics textbooks underlying the popularisation) show a pretty good degree of understanding.

As for measuring time. We rely on our (extensive) observation that lots of other processes in the universe correlate very well with the oscillation of the radiation...caesium-133 atom. So if the half life of a neutron is roughly 9 trillion cycles of that radiation one day, it seems to be the same the next day and in the next la

No to mention that it appears time/space/gravity/velocity are all inter-related and effect each other. 15 minutes at the speed of light is different than 15 minutes standing still.

Only from the frame of a outside observer. And if the universe is in an stage where it is expanding at 50% of the speed of light, how are you going to observe from an outside frame of reference? Also, 'standing still' is kind of tricky. Standing still compared to what? The expanding universe?

15 minutes at the speed of light is different than 15 minutes standing still.

If you had bothered to learn any relativity theory (over a century old, not exactly hot off the presses), you would be less completely confused. Sorry, you have to pay to play. As Euclid remarked, there is no "royal road to geometry", you actually have to learn some math and physical theories or your opinions really don't matter (in fact they are not even wrong). On the other hand none of the relevant knowledge is inaccessible (un

The only kind of people who equate knowledge with certainty are extreme rationalists and the uneducated (or unreflective) people who have never thought about how they use the word.

In my view as an empiricist, knowledge is possible without certainty, and indeed the vast majority of things we know are not certain. I know where I parked my car, and would go so far as to say I know where my car is right now. I know my name. I know what colour of socks I'm wearing. I know THAT I'm wearing socks. All of thes

Huh? We've never drilled deeper than a scratch; anything we "know" about the center of the earth is certainly something we deduce/extrapolate/theorize based on our model. Even without slipping into pure solipsism, surely what we "know" about the center of the earth is based on entirely the same sort of deduction you seem to reject for the Big Bang.

you wouldn't believe it reading the drivel that the popular press have been writing about it. you'd have thought the words "electron density" would have given it away that we're not talking dark matter here, but no. STUDENT FINDS MISSING MATTER scream the headlines. "ok, fair enough," you think. then the article is filled with things about dark matter. pah.

A student has found that if you observe in the x-ray range you discover ordinary matter between the galaxies that was clearly evident in the early universe and isn't visible in other parts of the spectrum.

I'm not sure that it's altogether news that different frequencies let you see different things - to me, by far the biggest news is that despite having x-ray telescopes for a very long time and computers quite capable of crunching that data to detect potentially interesting observations, the astronomers have been opting for cheap student labor instead.

The student got listed as first author, which is cool for her. The paper itself is a follow-up to Pimbblet's (the actual prof with the actual grant) 2004 study of filaments. The major finding seems to be that the press is gullible enough to print anything if you say an undergrad did the work. In this case, the press manages to avoid looking like total idiots, since the study is pretty cool and interesting. Nonetheless, the hype is vastly out of proportion to the significance.

You're wrong. To be listed first author is generally an indication that you did the bulk of the work for the paper. Middle authors are usually minor contributors to some extent, and the last few names are usually the professors who employ the students/postdocs.

It's not that you're wrong, you're just using different metrics. In physics (and astronomy, I think), the authors are usually listed in decreasing order of work done, starting with the person who did the most. The people at the end of the list have done so little work, why are they even on the paper? Because, as you say, they are listed in increasing order of importance (read: amount of grant money received). If you have enough people, sometimes they just throw them all into alphabetical order and pretend t

Well, no. I don't agree. An archaeologist in the field can't be replaced by a computer down the hallway. It is quite impossible for a computer to tell you what you will find if you dig 7 feet at position X. On the other hand, a computer and a human eye can equally spot abnormalities in an x-ray image of intergalactic space. (Computers cannot be better, as to prevent false positives and false negatives, the algorithm must be calibrated by eye and the positives then validated by eye. What they CAN do better i

It is quite impossible for a computer to tell you what you will find if you dig 7 feet at position X. On the other hand, a computer and a human eye can equally spot abnormalities in an x-ray image of intergalactic space.

That's the dumbest thing I've read in the past week on/. The only difference between your two scenarios is that you don't know of a sensor that can image what is 7 feet under at position X. Obviously you haven't seen Jurassic Park =p.

If I'm reading TFA correctly, this material is mass we already knew had to be around but didn't know where it had gone to. According to TFA, the student in question, Amelia Fraser-McKelvie, the mass in question is essentially conventional mass that is in so called "filaments" between galaxies.

The summary and article are making a mountain out of a mole hill. The student did good work but did not 'find the missing mass' in the universe. Here is a link to the publicly accessible article on arXiv:http://arxiv.org/abs/1104.0711 [arxiv.org]
The abstract does not make any grandiose claims of finding the missing mass of the universe but instead states how the article presents properties of mass in filaments.

Do you mean to imply that I belittled the article by providing the arXiv link? If so that was not my intent. arXiv provides the community with a repository of works from all journals in one convient (and free to access) location. That being said, the fact that it was accepted for publication is irrelevant to the discussion. The scientific article is fine and make reasonable claims, the popular article makes it sound like they solved a major mystery instead of confirming expectations with new data.

From TFA:"Whenever I speak to people who have influence, politicians and so on, they sometimes ask me 'Why should I invest in physics pure research?'. And I sometimes say to them: 'Do you use a mobile phone? Some of that technology came about by black hole research'."

So that explains why I can never retrieve the information that gets entered into my phone!

Or the standards of beauty include knowledge that the person in question is intelligent; some folks find intelligence to be attractive and desirable. Of course, for some people (impotent men, Slashdot ACs), "intelligent" = "ugly".

Why is it that the younger the person who does something, the more special people think it is? I call it the "America's Got Talent" effect.

At least in science it seems the body of human knowledge continues to expand. Like many of the math theorems that requires years of field theory and calculus to even understand WTF the theorem is about. Try for example reading the proof of Fermat's last theorem without developing a brain aneurysm. It's like they talk Greek and Latin and ancient Hebrew and something you could swear is alien.

That young people still discover things is proof there's still low hanging fruit or that exceptional talent matters more than a PhD and 20 years of working with the subject matter. Of course there's many cookie cutter professors too but usually there are some that are exceptional talents and PhDs and have worked on it 20 years who has picked clean any reasonably accessible discovery.

Same with for example physics, unless you're at the Tevatron or CERN it's unlikely you'll find any new elementary particles, add any new entries to the periodic table, build carbon nanotubes, high-temperature superconductors or anything else that will make a huge impact, compared to the relatively simple lab equipment 100 years ago. That's why the young ones are news, because they're the exceptions.

That young people still discover things is proof there's still low hanging fruit or that exceptional talent matters more than a PhD and 20 years of working with the subject matter. Of course there's many cookie cutter professors too but usually there are some that are exceptional talents and PhDs and have worked on it 20 years who has picked clean any reasonably accessible discovery.

What I think it means is that when you've been working on something so long you tend to lose focus on something obvious. It takes a fresh pair of eyes without a vested interest to make the connection.

Maybe because it's a genuine rarity. Older, more knowledge professionals make more scientific progress than young people. When young people, who are otherwise assumed to be worthless or even detrimental to society do something to progress academia or society, it's a notable event.

Is it? Einstein, Hawking, Nietzsche all did their greatest work before they got older. The man who invented the technology for the original mammogram was 27. It was my understanding that if you didn't do anything great by the time you turn 30, you're unlikely to achieve anything of note after that. Particularly in theoretical and academic realms.

Young people are usually less likely to rely in the previous generation dogmas, so they test everything. By pure statistics, some of them are intelligent enough and point at a direction right enough to find a new answer that would have been passed over by older scientifics. Also, they may be more blunt because they don't have a status to defend (non-euclidean geometry was several times discovered but people found it too 'weird' and chose not to publicite i

That thing you call "dogma" is called "learning enough to know what the fuck you're talking about". And often enough, "non-conformist thinking" is better known as "bullshit from basement-dwelling crackpots". The trick to telling the difference, you see, is learning enough to know what the fuck you're talking about. And not wasting limited time, energy, and resources on the dogma-free non-conformist thinkers like yourselves.

And yes, physicists are well-known for their extravagant, research grant-fueled

Actually it seems she didn't find anything: [paperblog.com] "Ms Fraser-McKelvie said the ‘Eureka moment’ came when Dr Lazendic-Galloway closely examined the data they had collected. “Using her expert knowledge in the X-ray astronomy field, Jasmina (Dr Lazendic-Galloway) re-analyzed our results to find that we had in fact detected the filaments in the results, where previously we believed we had not.”"

So the student found nothing, it wasn't until an expert looked at it and actually found the mass.

So I guess it depends on your perspective as to if the student found it or not. If you're throwing out a bunch of "junk" and an expert goes through it and discovers a priceless artifact does that mean you discovered it or did the expert?

CoralCache [nyud.net] has a mirror of the original. If you're one of the people who regularly Rs TFA and runs Firefox with Greasemonkey I recommend downloading a script that automatically rewrites/. links to use CC.

This is slashdot, no one reads TFA:)... we just make up opinions using car analogies (it's like if the student realized by accident where some of the missing mass of the universe was by opening the trunk of the car).

bonus points if you can use fancy mathematical equations and complicated terms to explain every day things:)

Wow a young woman seems to figure out one of the greatest mysteries of our era, you make a snarky comment implying that she's fat. That must be why there are so few 'geek' women, as the boys apparently go strait for the gut when a lady seems smarter than they. Sadly there doesn't seem to be much discussion about this that isn't sophomoric banter.

She says the ‘Eureka’ moment came after Dr Lazendic-Galloway examined the data collected. “Using her expert knowledge in the X-ray astronomy field, Jasmina reanalysed our results to find that we had in fact detected the filaments in our data, where previously we believed we had not.” Ms Fraser-McKelvie said in the press release.

This breakthrough discovery in determining the amount of mass contained in the filaments, as scientists have been making deductions based on numerical models until now.

Although she is still a year away from undertaking Honours, Ms Fraser-McKelvie’s work has been published in the prestigious scientific journal Monthly Notices of the Royal Astronomical Society, a terrific achievement for an undergraduate. “Being a published author is very exciting for me, and something I could never have achieved without the help of both Kevin and Jasmina.” she said.

“Their passion and commitment for this project ensured the great result and I am very thankful to them for all the help they have given me and time they have invested.”

From the original [scienceill...ted.com.au] article as posted on Science Illustrated's website.

Emphasis is mine but the quotes clearly point out her level of gratitude and humbleness or would you like to attach some other meaning to it?

That must be why there are so few 'geek' women, as the boys apparently go strait for the gut when a lady seems smarter than they. Sadly there doesn't seem to be much discussion about this that isn't sophomoric banter.

Guys insult guys on a regular and persistent basis, but they don't break down, cut their hair and transfer to Womyn's Studies. (Or whatever young women do who can't hack male-dominated domains.)